1. Field of the Invention
The invention relates to an air quality control system, in particular to an air quality control system for public areas of multi-unit buildings. The invention may be used to ensure that paths of egress are smoke-free, especially in the case of an emergency. The invention thus helps reduce the risk of death due to smoke inhalation. The invention can further be utilized as an odor and/or heat control system.
2. Description of the Related Art
Hallways and other public areas of apartment buildings, hotels, office buildings, nursing homes, hospitals, and the like, i.e. public areas of multi-unit buildings, must remain smoke-free and cool in the case of fires, since they very often provide the only paths of egress to the emergency exits. Several methods and devices have been disclosed which deal with the problem.
One of the methods for controlling smoke is to increase the ambient pressure by supplying fresh air. A system utilizing this method is disclosed in U.S. Pat. No. 3,926,101 to Moss. A hallway, which is partitioned into three sections is subjected to increased air pressure, which is to keep the smoke coming from an apartment within that apartment. Since no exhaust vents are provided, the smoke which had entered the hallway, and thus had triggered the smoke alarm, either remains in that hallway or is distributed to other, adjacent apartment units.
Several other U.S. Patents, such as U.S. Pat. No. 3,884,133 to Miller and U.S. Pat. No. 2,564,971 to Harding relate to fire control systems, whose primary purpose is the control of fires in multi-unit buildings.
One problem with the prior art devices is that they do not provide a system for removing smoke and other poisonous gases from escape routes and for re-supplying fresh air. Furthermore, none of the known systems relate specifically to the problem of handicapped people, who usually cannot use the stairs and therefore depend on the elevators as the only possibility of escape.
The prior art devices are also inadequate for odor and heat control when there is no fire, because the existing air is not removed and replaced with fresh air.